Clips to hold knobs on shafts

ABSTRACT

A CLIP TO HOLD A KNOB ON A D-SHAPED SHAFT HAS A GENERAL D-SHAPED CONFIGURATION SPLIT AND TAPERED FROM ONE END TO THE OTHER AND ADAPTED TO FRICTIONALLY FIT WITHIN A HOLLOW SECTION OF THE KNOB. A PEROJECTING TAB KIGS INTO THE INNER WALL OF THE HOLLOW SECTION OF THE KNOB TO MAINTAIN THE CLIP WITHIN THE KNOB. THE SPLIT TAPERED CONFIGURATION ALLOWS THE SHAFT TO BE EASILY INSERTED INTO THE CLIP AND BECOMES LESS TAPERED DURING INSERTION TO FRICTIONALLY ENGAGE AND HOLD THE CLIP WITHIN THE KNOB AND ONTO THE SHAFT.

Jan. 5,;1971 I R. G. LUNDERGAN- ETAL 3,552,784

CLIPS TO HOLD KNOBS ON SHAFTS Filed Sept. 4, 1969 I 2 Sheets-Sheet 1 INVENTOR 7 Frederick Jean Mal'rais etdl Jan. 5, 1971 Filed Sept. 4, 19 9 R. G. LUNbERGAN ET AL 3,552,784

CLIPS -TO HOLD KNOBS ON SHAFTS 2 Sheets-Sheet 2' I/VVE/VTOR Frederick Jean Muliuis e1 0| Bram 4 we United States Patent 'ce Patented Jan. 5, 1971 a 3 552 784 FIG. 4 is a view similar to FIG. 3 with the knob on the CLIPS T0 noLi) Kisoas 0N SHAFTS end the Shaft;

Robert Graham Lundergan, 'Camp Hill, Eugene Leonard Gombar, Harrisburg, and Frederick Jean Maltais, Camp Hill, Pa., assignors to AMP Incorporated, Harrisburg,

Filed Sept. 4, 1969, Ser. No. 855,228 Int. Cl. F16d 1/06 U.S Cl. 287 53 5 Claims ABSTRACT OF THE DISCLOSURE This invention generally relates to fastening or clip means for use to connect knobs to shafts and relates particularly to the retention clips used as a connecting device to mate and secure such knobs to a shaft.

Retention clips of this general type are common, as shown in the Hansen Pat. No. 2,968,504. However, due to the industrys need to use automatic application capability, prior art is no longer ideal, for the reasons that these prior art'clips are not readily susceptible to being used in an applicator device for applying them into knobs, they are not provided in strip form for use in the applicator device, the configuration of the clips does not lend them to ready insertion in the knobs.

Therefore a primary object of the present invention is to provide a suitable retaining clip which may easily be handled by automatic applicator machinery.

A further object of the invention is to provide a clip such as to accommodate varying tolerances and discrepancies inherent in manufacture.

Another object is the provision of a clip with means to prevent rotary and axial movement between the shaft and the knob and which requires a minimum in tooling and is therefore inexpensive and easy to manufacture.

Still another object is to provide a clip with means to secure to clip in the knob such that axial and rotary movement between the clip and the knob is precluded.

Still a furtherobject is to provide a clip which may be secured permanently within a knob and may be removed from a shaft and re-used when required.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

Referring to the drawings:

FIG. 1 is a perspective and exploded view of an end of the shaft, clip and knob according to the invention;

FIG. 2 is a front end view of the clip;

FIG. 3 is a longitudinal cross-sectional view of a knob with inserted clip;

FIG. 5 is a view taken along the lines 55 of FIG. 4; and

FIG. 6 is a perspective view of two clips shown in strip form.

Referring to FIGS. 1 and 2, there is shown a clip C used to secure knob K onto shaft S. Clip C is formed out of spring steel or some similarly suitable material possessing the required spring characteristics and may be mass produced by fully automatic machinery. The clip C is formed in a progressive die and manufactured in continuous strip CS, as shown in FIG. 6, which has holes H therein to be engaged by the feed mechanism of an automatic applicator device to feed the strip so that clips C are successively fed to a station at which the clips are severed from the strip and inserted within knobs. In the form of the invention, as shown, the clip C is of generally split tubular form and it is tapered from the trailing end 1 to the leading end 2.

A transverse cross-section shows a channel U provided with a curved base 3 and sidewalls 4 and 5 having outwardly-extending portions 6 and 7 at the outer ends thereof. The portions 6 and 7 provide horizontal support portions which extend upwardly into opposing arcuate members 8 and 9 which in turn terminate in flattened sections 10 and 11. Sections 10 and 11 are raised at the trailing end -1 of clip C to include outwardly-projecting and beveled corners 12 and 13. U-shaped channel 3 has an outwardly-curved tab 14 at the trailing end. Portions 6 and 7, arcuate members 8 and 9 and sections 10 and 11 of clip C define a section D.

In use the clip is severed from the strip at tab 14 and inserted by means of a mandrel of an applicator device (not shown) into a large opening 15 of knob K. Supporting shoulders 16 projecting from the wall of opening 15 engage support portions 6 and 7 of the clip. Also flattened sections 10 and 11 frictionally engage the wall of D-shaped section 18 of opening 15 in which the D- shaped part of clip C is disposed. After complete insertion of the clip C into knob K, pressure caused by the spring features of the outwardly-projecting corners 12 and 13 at the trailing end of the clip forces tab 14 to dig into the wall of U-shaped section 17 in which the channel U is disposed. This arrangement firmly and permanently holds the clip within the knob and prevents all possible axial and rotational movement.

It is to be understood that the inner diameter of opening 15 is intermediate the outer tubular dimensions of the ends of the clip C. Therefore, although tapered end 2 will easily slide into opening 16 with little force, as insertion of the clip progresses greater friction is experienced between the outer dimensions of the clip C and the wall of opening 15 which increases, particularly as upward-projection corners 12 and 13 engage the inner wall of the knob. Corners 12 and 13 assure that tab 14 maintains a biting engagement with the wall of opening 15. After insertion of the clip within the knob, the clip, although somewhat straightened, still retains most most of its taper.

The enlarged trailing opening of the clip still has a greater inner diameter than the outer dimensions of a D-shaped end of shaft S. Thus, as the clip is placed over the end of the shaft, with the D-shaped section of the clip alignetd generally with the corresponding configuration of the shaft, little effort is required to loosely achieve a partial slideable engagement. As greater force is applied at the end 19 of knob K, shaft S experiences greater friction as it is being moved toward the leading end 2 of the clip. By forcing the clip onto the end of the shaft, the inner diameter of the clip is increased to accommodate the shaft. Due to the tapered configuration and the spring characteristics of the clip, the trailing 'end 1 of the clip in turn counteracts to envelope the shaft with increased frictional force. The clip with the shaft in position in the knob places the clip under a residual pressure thereby frictionally retaining the knob on the shaft and increasing the retention forces of the clip on the wall of opening 15.

It should be readily apparent that small variations in the tolerances of the shaft, knob or clip, which are inherent in the manufacture thereof, will not appreciably effect the performance of the clip relative to the shaft or knob. Moreover, the knob and the clip therein may be removed and re-used when required. The outwardlydirected disposition of corners 12 and 13 when in knob K facilitates entry of the D-shaped end of shaft S within the clip C.

It will, therefore, be appreciated that the afore-mentioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

The invention is claimed in accordance with the following:

1. A clip for securing a knob to a D-shaped end of a shaft comprising a longitudinally split, resilient and tubular member having first and second longitudinal sections, said member being tapered from an area adjacent a leading end to a trailing end thereof, said first longitudinal section having a substantially D-shaped configuration and said second section having a U-shaped configuration.

2. A clip for securing a knob to a D-shaped end of a shaft comprising a longitudinally split, resilient and tubular member having first and second longitudinal sections, said member being tapered from an area ad- *jacent'a' leading'end'to a 'trailing'end thereof"; said-first longitudinal section having a substantially D-shaped configuration, and said second section having a U-shaped configuration, said U-shaped section having upwardly-directed sidewalls which terminate into outwardly-directed coplanar fianges, said flanges comprising the base of said D-shaped section, said D-shape'd vsection :being Ion tudinally split at the apex of its curvature. g

3. A clip as defined in claim 2 wherein the tubular member includes a tab which is disposediat one end of the member and which projects outwardly therefrorrrto engage and maintain said clip by frictional force within said knob.

4. A clip as defined in claim} whereinsaid tab is disposed at the trailing end and in acurved base of said U-shaped member. I I

5. A clip as defined in claim 3 wherein said clip ineludes resilient projection means comprisingv outwardly; directed portions located at the apex-0f said curyature at the trailing end of the clip, said portions adapted to engage an inner wall of the knob to maintain said tab in biting engagement with the inner wall.-

References Cited UNITED STATES PATENTS 2,080,361 5/1937 Lindstrorn 28753H 2,745,689 5/1956 Balint et a1. 28753H 2,968,504 1/1961 Hansen 2 87-' 53H DAVID J. WILLIAMOWSKY, Primary Examiner f i A. V. KUNDRAT, AssistantExaminer US. Cl. X.R. 

